Zipper tape and package bag with zipper tape

ABSTRACT

A head of a male member and a concave groove of a female member are engageable with and disengageable from each other and form a containing space inside a bag body. On an inner surface of the concave groove, there is provided a fusion layer that fuses an outer surface of the head and the inner surface of the concave groove facing each other, when foods are heat-sterilized for long storage. A peeling strength of the fusion layer only needs to be set by selecting a material of the fusion layer or setting dimensions of an area of the fusion layer such that the fusion layer does not require a large force for opening the bag, thereby providing a favorable opening feeling. The fusion layer provides air-tightness, so that the foods can be prevented from leaking out although a pressure within the containing space is increased in the heat sterilization.

TECHNICAL FIELD

The present invention relates to a zipper tape and a packaging bagprovided with the zipper tape.

BACKGROUND ART

There has been typically known a packaging bag with a zipper tape(hereinafter occasionally abbreviated as a packaging bag) provided bybonding the zipper tape to an inner surface of the bag body. When such apackaging bag is filled with powdery substances and liquids as contents,the contents may leak toward a top seal beyond the zipper tape duringtransportation, or external air may infiltrate into the packaging bag toalter the quality of the contents.

Accordingly, in order to prevent leakage of the contents and maintainthe quality of the contents by blocking external air, a zipper tapehaving a structure for improving air-tightness and a packaging bag withthe zipper tape have been known (see Patent Literatures 1 to 3).

Patent Literature 1 discloses that a flexible rubber packing is providedon each of facing engagement-surfaces of male and female members alongthe longitudinal direction of the zipper tape. When the male and femalemembers are engaged with each other, the respective flexible rubberpacking are elastically deformed by being pressed between and by thefacing engagement-surfaces to be brought into close contact with thefacing engagement-surfaces, so that air-tightness can be obtained.

Patent Literature 2 discloses that an elastic adhesive material iscontinuously provided on an inner bottom of a female protrusion of afemale member along the longitudinal direction of a zipper tape. When amale protrusion of a male member is engaged with the female protrusion,the elastic adhesive material of the female protrusion is pressed by ahead of the male protrusion to be brought into close contact with thehead of the male protrusion by elastic force of the elastic adhesivematerial, so that air-tightness can be obtained.

Patent Literature 3 discloses that an easily peelable plastic layerformed of polybutene, an ethylene-vinyl acetate copolymer, anethylene-polypropylene mixture and the like is provided on a surface ofa male protrusion, and the easily peelable plastic layer providesair-tightness in engagement. The easily peelable plastic layer isconfigured to allow cohesive peeling or interfacial peeling in opening.

CITATION LIST Patent Literature(s)

Patent Literature JP-A-6-239356

Patent Literature 2 JP-A-2006-102068

Patent Literature 3 Pamphlet of International Publication WO02/38459

SUMMARY OF THE INVENTION Problems To Be Solved by the Invention

Examples of contents to be fed into a packaging bag with a zipper tapeinclude: foods to be heated by a retort process, a boiling process orthe like for sterilization; and pharmaceutical products, medicalproducts, cosmetics, chemical products and groceries to be heated forsterilization.

In such cases, for instance, in the packaging bag with the zipper tapeincluding the elastic member as disclosed in Patent Literatures 1 and 2,the elastic member is easily deformed by heat in a heating process, sothat a gap may be formed between the elastic member and an engagementportion to impair air-tightness. Moreover, since the elastic member isused, odor may be generated from the elastic member in the heatingprocess, which may make a user uncomfortable. In Patent Literature 2,since a tackifier is contained in the elastic member, the contents maybe adhered to the elastic member of the zipper tape when opening thepackaging bag.

On the other hand, in such an arrangement as disclosed in PatentLiterature 3 in which the easily peelable plastic layer to be bonded isprovided, if the easily peelable plastic layer is bonded by a bondingstrength enough to resist internal pressure in the heating process, alarge force is required to peel the easily peelable plastic layer inopening the bag, which may impair openability of the bag. Moreover,since the easily peelable plastic layer that is already bonded to themale protrusion is attached to a bag body to form a packaging bag with azipper tape, a method for feeding the contents is limited to, forinstance, feeding the contents from the bottom of the bag, so thatversatility may not be improved.

In consideration of the above, an object of the invention is to providea zipper tape of which air-tightness and openability are not adverselyaffected even in the heating process, and a packaging bag with thezipper tape.

Means for Solving the Problems

According to an aspect of the invention, a zipper tape includes: a pairof a male member and a female member that are engageable with anddisengageable from each other, the zipper tape being provided to a bagbody that contains an object to be heated, in which at least one of themale member and the female member includes a fusion layer that fusesengagement contact surfaces of the male member and the female memberwhen heating the object.

With this arrangement, the fusion layer preferably has a melting pointfrom 60 degrees C. to 150 degrees C.

According to another aspect of the invention, a zipper tape includes: apair of a male member and a female member that are engageable with anddisengageable from each other, in which at least one of the male memberand the female member includes a fusion layer capable of fusingengagement contact surfaces of the male member and the female member,the fusion layer being formed of a resin having a melting point from 60degrees C. to 150 degrees C. lower than a melting point of each of themale member and the female member.

With this arrangement, the fusion layer is preferably formed of at leastone of an ethylene-vinyl acetate copolymer resin and metallocene-typelinear low-density polyethylene.

With this arrangement, the fusion layer is preferably provided in a lineso as to be in linear contact with the engagement adhesion surfacesalong a longitudinal direction of the tape.

Moreover, with this arrangement, the fusion layer is preferably providedin a film so as to be in surface contact with the engagement adhesionsurfaces along a longitudinal direction of the tape.

According to a still another aspect of the invention, a packaging bagincludes: a bag body; and the zipper tape according to the above aspectof the invention which is attached to the bag body.

Advantage(s) of the Invention

According to the invention, since the engagement contact surfaces of themale member and the female member are fused through the fusion layer inthe heating process, no gap is formed in the engagement portion betweenthe male member and the female member, so that air-tightness can beobtained. Further, since the bag is openable by peeling the fusionlayer, a peeling strength of the fusion layer only needs to be set byselecting a material of the fusion layer and setting dimensions of anarea of the fusion layer such that the fusion layer does not require alarge force for opening the bag to deteriorate an opening feeling.Accordingly, air-tightness can be improved in the heating processwithout impairing the opening feeling. Moreover, by appropriatelyselecting the material of the fusion layer, a user can be prevented fromfeeling uncomfortable because of characteristic odor of an elasticmember.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view showing a packaging bag provided with a zippertape according to an exemplary embodiment of the invention.

FIG. 2 is a cross-sectional view taken along II-II in FIG. 1.

FIG. 3 is a partially-cut cross-sectional view showing a vicinity of apackaging bag provided with a zipper tape according to another exemplaryembodiment of the invention.

FIG. 4 is a partially-cut cross-sectional view showing a vicinity of apackaging bag provided with a zipper tape according to still anotherexemplary embodiment of the invention.

FIG. 5 is a partially-cut cross-sectional view showing a vicinity of apackaging bag provided with a zipper tape according to a furtherexemplary embodiment of the invention.

FIG. 6 is a partially-cut cross-sectional view showing a packaging bagprovided with a zipper tape according to a still further exemplaryembodiment of the invention.

FIG. 7 is a cross-sectional view showing a packaging bag provided with azipper tape according to a still further exemplary embodiment of theinvention.

DESCRIPTION OF EMBODIMENT(S)

A packaging bag provided with a zipper tape according to an exemplaryembodiment of the invention will be described with reference to theattached drawings.

In this exemplary embodiment, the packaging bag provided with the zippertape (hereinafter, abbreviated as a “packaging bag”) is exemplified by apackaging bag for packaging foods to be heat-sterilized (to be heated)in a retort process or a boiling process. However, the packaging bag isalso applicable for containing an object such as pharmaceuticalproducts, medical products, cosmetics, chemical products and groceriesto be heat-sterilized (to be heated).

Arrangement of Packaging Bag

A packaging bag 1 according to the exemplary embodiment is filled withfoods (i.e., an object) such as a retort food to be heat-sterilized forlong storage. Examples of the foods to be contained include cooked foodsto be heated for long storage and uncooked foods, in either solid orliquid form. As shown in FIG. 1, the packaging bag 1 includes a bag body10 provided by layering base films 11 (packaging material) one on theother and forming side seal bases 12, a bottom seal base 13 and a topseal base 14 on the periphery of the base films 11.

As shown in FIGS. 1 and 2, a zipper tape 20 including a pair of a malemember 21 and a female member 22 is attached to an inner surface 10A ofan opening portion 15 of the bag body 10. The zipper tape 20 is sealedto the bag body 10 in a belt from one of the side seal bases 12 to theother of the side seal bases 12. An engageable and disengageableengagement portion 23 of the zipper tape 20 defines a containing space16 inside the packaging bag 1.

After foods (not shown) are contained through a bottom of the bag body10, the bottom seal base 13 is formed on the bottom side of the bag body10 to provide a hermetically sealed condition.

For opening the bag, a user cuts off the top seal base 14 provided nearthe opening portion 15, and reseals the bag with the zipper tape 20.

As described above, the zipper tape 20 includes the male member 21provided on one side and the female member 22 provided to the other sideto be engaged with the male member 21, the male and female members 21and 22 each formed of a thermoplastic resin and having a belt-likeshape.

The male member 21 includes: a male belt-like base 211 sealed to the bagbody 10; a head 212 having a substantially arrow shape in cross section;and a connecting portion 213 that connects the male belt-like base 211and the head 212. The belt-like base 211, the head 212 and theconnection portion 213 integrally forms the male member 21.

Similarly to the male member 21, the female member 22 includes: a femalebelt-like base 221 sealed to the bag body 10; and a concave groove 222having an arc shape in cross section that is connected to the femalebelt-like base 221. The concave groove 222 is engageable with anddisengageable from the head 212 of the male member 21. The concavegroove 222 and the head 212 provide an engagement portion 23. Byengagement or disengagement between the concave groove 222 and the head212, the packaging bag 1 is sealed or opened.

Herein, the male member 21 of the zipper tape 20 of the exemplaryembodiment can be obtained by co-extrusion, where the male belt-likebase 211 and the head 212 and the connecting portion 213 that are formedcontinuously from the male belt-like base 211 are integrally formed.Likewise, the female member 22 can also be obtained by co-extrusion,where the female belt-like base 221 and the concave groove 222 formedcontinuously therefrom are integrally formed. When the zipper tape 20 isformed by such co-extrusion, the zipper tape 20 can be manufactured in asimplified process at low costs, and can be stably manufactured in acontinuous manner.

The male member 21 and the female member 22 of the zipper tape 20 may beformed of polyethylene and polypropylene and are preferably formed ofhighly heat-resistant polypropylene. Specifically, thermoplastic resinssuch as homo-polypropylene, block-polypropylene (hereinafter,abbreviated as “BPP”), random polypropylene (hereinafter, abbreviated as“RPP”), propylene-ethylene-butene-1 random terpolymer andpolyolefin-based special flexible resins (hereinafter, abbreviated as“TPO resins,” e.g., TPO manufactured by Prime Polymer Co., Ltd.), and amixture thereof are usable.

When RPP is used as the resin forming the zipper tape 20, a melt flowrate ((hereinafter, abbreviated as “MFR”) of RPP is preferably 0.5 g/10min to 20 g/10 min, particularly preferably 1 g/10 min to 15 g/10 min.

When MFR of RPP is less than 0.5 g/10 min, extrusion formability of theengagement portion 23 that is continuously and integrally formed withthe male belt-like base 211 and the female belt-like base 221 may bedeteriorated. On the other hand, when MFR is more than 20 g/10 min, tipends of the concave groove 222 of the female member 22 may be easilyclosed and the connecting portion 213 of the male member 21 may beeasily bent, which makes it difficult to extrude the engagement portion23 into a predetermined reopenable/resealable shape.

Further, a fusion layer 24 is provided on an inner surface of theconcave groove 222 of the female member 22. The fusion layer 24 ismelted by heat when heat-sterilizing the contained foods, whereby anouter surface (i.e., engagement contact surface) of the head 212 and aninner surface (i.e., engagement contact surface) of the concave groove222 are fused, the engagement contact surfaces being engaged with eachother and facing each other.

The fusion layer 24 is made of a resin having a melting point of 60degrees C. to 150 degrees C. In other words, the usable resin is, forinstance, such a resin as are melted at the temperature of approximately60 degrees C. to 100 degrees C. for the boiling sterilization or at thetemperature of 100 degrees C. to 150 degrees C. for the heatsterilization of retort foods to be cooked with a microwave oven.Specifically, at least one of an ethylene-vinyl acetate copolymer resin(hereinafter, abbreviated as “EVA”) and metallocene-type linearlow-density polyethylene (hereinafter, abbreviated as “metallocene LL”)is usable.

When the melting point of the fusion layer 24 is lower than 60 degreesC., the melted fusion layer 24 may leak out of the engagement portion23. On the other hand, when the melting point of the fusion layer 24 ishigher than 150 degrees C., the fusion layer 24 is not melted when foodsare heat-sterilized. In other words, it is not possible to fuse theengagement contact surfaces of the head 212 and the concave groove 222by heat-melting the fusion layer 24 for the heat sterilization, so thatsealability cannot be improved. For instance, foods may leak out of agap between the head 212 and the concave groove 222 by the internalpressure increased by heat for the heat sterilization. For this reason,the fusion layer 24 is made of a material having a melting point of 60degrees C. to 150 degrees C.

The fusion layer 24 is provided in a line so as to be in linear contactwith the engagement adhesion surfaces along the longitudinal directionof the tape. Specifically, plural lines (e.g., three lines) of thefusion layers 24 are provided along the longitudinal direction of thezipper tape 20 from one of the side seal bases 12 to the other of theside seal bases 12.

By sealing the thus configured zipper tape 20 to the base film 11 of thebag body 10 and forming the base film 11 into a bag, the packaging bag 1as shown in FIG. 1 can be obtained. When the zipper tape 20 is sealed onthe base film 11, the fusion layer 24 is melted by heat (radiant heat)during welding, for instance, with a seal bar, whereby the engagementcontact surfaces of the head 212 of the male member 21 and the concavegroove 222 of the female member 22 are fused to each other through thefusion layer 24.

While the base film 11 (packaging material) for forming the bag body 10is preferably a layered film, for instance, in which a sealant layer islayered onto a base layer (not shown), the base film 11 may be a layeredfilm in which a layered film layer (not shown) including layers of a gasbarrier layer, a light-shielding layer and a strength-reinforcing layeris provided as a middle layer between the base layer and the sealantlayer, depending on a required performance. The base film 11 is made ofa resin having a higher melting point than the fusion layer 24.Specifically, the base film 11 is made of a resin capable of remainingunmelted during the heat sterilization. As this resin, not only one kindof a resin is usable, but also a mixture of various resins and acopolymerized substance are usable.

Examples of the material for the base layer are preferably abiaxially-oriented polypropylene film (hereinafter, abbreviated as an“OPP film”), a biaxially-oriented polyester film such asbiaxially-oriented polyethylene terephthalate film (hereinafter,abbreviated as a “PET film”) and biaxially-oriented polyethylenenaphthalate film and a biaxially-oriented polyamide film such as nylon6, nylon 66 and MXD6 (poly-meta-xylylene adipamide). Depending on needs,various engineering plastic films are also usable. One of the above maybe used alone, or a combination of two or more of the above may belayered in use.

When the middle layer is a gas barrier layer, usable examples of thematerial for the middle layer are a film of a saponified ethylene-vinylacetate copolymer (hereinafter, abbreviated as “EVOH”) orpolyacrylonitrile (hereinafter, abbreviated as “PAN”), aluminum foil, adeposited layer of silica, alumina or aluminum and a coating layer ofPVDC.

When a deposited layer of silica, alumina or aluminum or a coating layerof PVDC is used, the deposited layer and the coating layer may be formedon the inner surface 10A of the bag body 10 of the base layer bydeposition or coating. Alternatively, a deposited layer and a coatinglayer may be formed on another biaxially-oriented nylon film(hereinafter, abbreviated as an “ONy film”), a PET film or an OPP filmby deposition or coating, and the film may be layered on the middlelayer.

Among the above, aluminum foil and a deposited layer of aluminum, whichare opaque, can also serve as a light-shielding layer.

The layering of the base layer and the film of the middle layer can beconducted by a known dry lamination method or extrusion laminationmethod (sandwich lamination method).

For the sealant layer (the innermost layer), polypropylene (hereinafter,abbreviated as “CPP”) and the like are usable.

In order to layer the sealant layer, the above resins may be formed intofilms and layered by a dry lamination method or extrusion laminationmethod. Alternatively, the above resins may be layered thereon byextrusion coating.

The packaging bag 1 according to this exemplary embodiment can be easilymanufactured with use of, for instance, a bag-making machine forthree-sided sealing and attaching the zipper tape.

Sealing conditions (temperature, pressure, etc.) in the manufacturingcan be properly determined in accordance with types of the resins forforming the zipper tape 20 and the base film 11 for forming the bag body10.

Opening and Resealing Operation of Packaging Bag

Firstly, the packaging bag 1 is heat-sterilized for long storage of thefoods contained therein.

By this heat sterilization, the fusion layer 24 is melted to fuse thefacing engagement contact surfaces of the head 212 of the male member 21and the concave groove 222 of the female member 22, in which the head212 and the concave groove 222 are engaged with each other.

The user cuts off the top seal base 14 to open the opening portion 15and takes out the heat-sterilized foods.

For resealing the packaging bag 1 containing left-over foods, the head212 and the concave groove 222 are re-engaged to seal the openingportion 15.

Here, melting of the fusion layer 24 during the heat sterilizationimproves engagement strength and air-tightness between the head 212 andthe concave groove 222. Accordingly, even if the internal pressurewithin the containing space 16 is increased by the heat sterilization,the foods does not leak out, for instance, through a gap between thehead 212 and the concave groove 222.

Moreover, by forming the fusion layer 24 of EVA or metallocene LL, acharacteristic odor of a conventional elastic member is not generatedduring the heat sterilization. Accordingly, the user can be preventedfrom feeling uncomfortable.

By pulling the opening portion 15 apart by pinching opening edgesthereof, the head 212 and the concave groove 222 which are fused throughthe fusion layer 24 are peeled away to release the engagement, so thatthe opening portion 15 is opened. The foods contained inside are takenout under this condition.

Advantages of Embodiment(s)

According to this exemplary embodiment, the following advantages can beobtained.

Specifically, in the above exemplary embodiment, in relation to the head212 of the male member 21 and the concave groove 222 of the femalemember 22 that are engageable with and disengageable from each other,the fusion layer 24 is provided on the inner surface of the concavegroove 222. When the foods are heat-sterilized for long storage, thefusion layer 24 fuses the outer surface (i.e., the engagement contactsurface) of the head 212 and the inner surface (i.e., the engagementcontact surface) of the concave groove 222, the outer surface and theinner surface facing each other.

Thus, since the fusion layer 24 fuses the engagement contact surfaces ofthe head 212 of the male member 21 and the concave groove 222 of thefemale member 22, no gap is formed in the engagement portion between thehead 212 of the male member 21 and the concave groove 222 of the femalemember 22, so that air-tightness can be obtained. Further, since the bagis openable by peeling the fusion layer 24, a peeling strength of thefusion layer 24 only needs to be set by selecting a material of thefusion layer 24 or setting dimensions of an area of the fusion layer 24such that the fusion layer 24 does not require a large force for openingthe bag to deteriorate an opening feeling. Accordingly, sealability bythe heating process can be improved without deteriorating the openingfeeling. In other words, the peeling strength is easily adjusted by anarrangement of the fusion layer 24, so that such an arrangement with afavorable opening feeling and air-tightness can be easily obtained.

In the exemplary embodiment, the bag contains foods to beheat-sterilized for long storage and includes the fusion layer 24 havinga melting point of 60 degrees C. to 150 degrees C.

With this arrangement, the fusion layer 24 can be suitably melted at thetemperature of the heat sterilization (heating process) in the boilingprocess, the retort process or the like, whereby the engagement contactsurfaces of the head 212 and the concave groove 222 can be fused to eachother. Accordingly, the foods can be prevented from leaking out of thegap between the head 212 and the concave groove 222.

In the exemplary embodiment, EVA and metallocene LL are used as thefusion layer 24.

Accordingly, characteristic odor of the elastic member is not generatedduring the heat sterilization to prevent the user from feelinguncomfortable.

Moreover, in the exemplary embodiment, three lines of the fusion layers24 are provided on the engagement contact surfaces of the head 212 andthe concave groove 222.

In comparison with an arrangement of a single line of the fusion layer24, this arrangement can provide a higher hermetically-sealed conditionagainst the outside of the containing space 16. Moreover, in comparisonwith an arrangement in which the outer surface of the head 212 and theinner surface of the concave groove 222 are entirely fused to eachother, this arrangement can provide a sufficient hermetically-sealedcondition even with less amount of a material. Further, in comparisonwith the arrangement in which the outer surface of the head 212 and theinner surface of the concave groove 222 are entirely fused to eachother, this arrangement requires only a small force for opening theopening portion 15 and can provide a lighter and favorable openingfeeling.

In the exemplary embodiment, the fusion layer 24 is provided on theconcave groove 222.

Accordingly, the food, even in a liquid form, is unlikely to be broughtinto contact with the fusion layer 24, so that inconvenience to make theuser feel uncomfortable can be prevented.

Modification

The scope of the invention is not limited to the above-describedembodiments but also includes modifications and improvements as long asan object of the invention can be achieved.

The arrangement with three lines of the fusion layers 24 is exemplarilydescribed. However, only a single line of the fusion layer 24 may beprovided as shown in FIG. 3, or two lines of the fusion layers 24 may beprovided as shown in FIG. 4.

The fusion layer 24 may be provided not only at the top of the head 212but also at both longitudinal sides of the head 212 as shown in FIG. 4.

Further, as shown in FIG. 5, the fusion layer 24 may be provided in afilm in a manner to cover substantially the entire area of the facingsurfaces of the head 212 and the concave groove 222. With thearrangement shown in FIG. 5, a higher sealability can be obtained.

Although the fusion layer 24 is provided on the concave groove 222, thefusion layer 24 may be provided on the outer surface of the head 212 ormay be provided on each of the head 212 and the concave groove 222.

When the fusion layer 24 is provided on each of the head 212 and theconcave groove 222, the fusion layer 24 of the head 212 and the fusionlayer 24 of the concave groove 222 are preferably provided at separatepositions so as not to face each other, in order to efficiently obtain ahigher sealability using less amount of the material.

For instance, as shown in FIG. 6, a packaging bag with a zipper tape 43may include a cutting tape 41 and a zipper tape 42 that is provided onone of the base films 11 of the bag body 10. As shown in FIG. 6, thezipper tape 42 may include plural lines (e.g., two lines) of engagementportions 23A and 23B.

The zipper tape 42 shown in FIG. 6 includes the fusion layer 24 on theengagement portion 23A near the containing space 16. The fusion layer 24may be provided on the engagement portion 23B near the opening portion15, or may be provided on each of the engagement portions 23A and 23B.

When the fusion layer 24 is provided on the engagement portion 23A nearthe containing space 16 as shown in FIG. 6, a high sealability isobtained using a relatively less amount of the material.

Moreover, as shown in FIG. 7, the male belt-like base 211 and the femalebelt-like base 221 including the plural lines (e.g., two lines) of theengagement portions 23A and 23B are attached to the base film(s) 11 ofthe bag body 10 by a seal section. The seal section may be provided toboth the male belt-like base 211 and the female belt-like base 221 nearthe opening of the bag body 10 while being provided only to one of themale belt-like base 211 and the female belt-like base 221 near thecontaining space 16.

With the arrangement shown in FIG. 7, a higher sealability can beobtained.

INDUSTRIAL APPLICABILITY

The invention is applicable to a zipper tape attached to a bag body tobe filled with foods, medicines and the like to be heated forsterilization and the like.

EXPLANATION OF CODES

-   -   1, 43, 52 packaging bag with a zipper tape    -   10 bag body    -   20, 42, 51 zipper tape    -   21 male member    -   22 female member    -   24 fusion layer

1. A zipper tape comprising: a pair of a male member and a female memberthat are engageable with and disengageable from each other, the zippertape being provided to a bag body that contains an object to be heated,wherein at least one of the male member and the female member includes afusion layer that fuses engagement contact surfaces of the male memberand the female member when heating the object.
 2. The zipper tapeaccording to claim 1, wherein the fusion layer has a melting point from60 degrees C. to 150 degrees C.
 3. A zipper tape comprising: a pair of amale member and a female member that are engageable with anddisengageable from each other, wherein at least one of the male memberand the female member includes a fusion layer capable of fusingengagement contact surfaces of the male member and the female member,the fusion layer being formed of a resin having a melting point from 60degrees C. to 150 degrees C. lower than a melting point of each of themale member and the female member.
 4. The zipper tape according to claim2, wherein, the fusion layer is formed of at least one of anethylene-vinyl acetate copolymer resin and metallocene-type linearlow-density polyethylene.
 5. The zipper tape according to claim 1,wherein the fusion layer is provided in a line so as to be in linearcontact with the engagement contact surfaces along a longitudinaldirection of the tape.
 6. The zipper tape according to claim 1, whereinthe fusion layer is provided in a film so as to be in surface contactwith the engagement contact surfaces along the longitudinal direction ofthe tape.
 7. A packaging bag comprising: a bag body; and the zipper tapeaccording to claim 1 which is attached to the bag body.
 8. The zippertape according to claim 3, wherein, the fusion layer is formed of atleast one of an ethylene-vinyl acetate copolymer resin andmetallocene-type linear low-density polyethylene.
 9. The zipper tapeaccording to claim 3, wherein the fusion layer is provided in a line soas to be in linear contact with the engagement contact surfaces along alongitudinal direction of the tape.
 10. The zipper tape according toclaim 3, wherein the fusion layer is provided in a film so as to be insurface contact with the engagement contact surfaces along thelongitudinal direction of the tape.
 11. A packaging bag comprising: abag body; and the zipper tape according to claim 3 which is attached tothe bag body.